The People's Perspective on Medicine

Cascara Sagrada

Cascara sagrada, once a popular though harsh laxative, is no longer permitted in over-the-counter medications in the US.
Cascara sagrada Rhamnus purshiana , or persian bark, medicinal plant. Hand drawn botanical vector illustration

Cascara sagrada, Spanish for “sacred bark,” comes from the American buckthorn tree (Rhamnus purshiana) native to the western coast of North America, from California to British Columbia, and as far inland as Montana. The Spanish priests of California may have learned about it from the Indians. Its primary use has been as a laxative.

In any event, this laxative was not widely adopted until the nineteenth century. A member of the same genus, R. frangula, is the European buckthorn tree, which had been used at least since 1650.

Cascara sagrada is one of the few herbs approved as an over-the-counter drug by the U.S. Food and Drug Administration. The portion of the plant used is the bark.

Active Ingredients:

The main ingredients are anthraquinones.

Emodin and aloe-emodin have also been identified, along with a number of nonlaxative ingredients.


Cascara sagrada was used as a laxative starting in the nineteenth and throughout the twentieth centuries. The anthraquinones stimulate the bowel, leading to evacuation after approximately six to ten hours. This herb also provokes secretion of fluid and minerals into the large intestine and inhibits their reabsorption. It was suggested for situations in which a soft, easily passed stool is desirable, such as hemorrhoids or following rectal surgery.

Cascara sagrada is not appropriate for regular use and can cause problems such as dependence if it is used too often. In 2002, the FDA issued a finding banning its use from over-the-counter medications. (Aloe vera was included in the same determination.) 

In addition, anthraquinones applied topically can protect skin from ultraviolet damage.

Extracts of R. purshiana can inactivate herpes simplex virus, but this property has not been utilized medically.

Recent research suggests that some components of R. purshiana, specifically emodin, may have anticancer activity (Cell Physiology and Biochemistry, Aug. 10, 2018; Biomedicine & Pharmacotherapy, Nov. 2018; Molecular Medicine Reports, Sep. 2018). More research is necessary before it is ready for clinical use, however.


The usual dose ranges from 20 mg to 70 mg daily of the anthraquinones. Products containing cascara sagrada should not be used for more than eight or ten days.

Special Precautions:

Fresh bark can cause nausea and vomiting. The bark should be stored for at least a year or undergo heat processing to eliminate this problem.
Pregnant women and nursing mothers should avoid cascara sagrada.

People with intestinal blockage, undiagnosed stomach pain, or symptoms that might indicate appendicitis must avoid laxatives such as cascara sagrada.

People with diarrhea, inflammatory bowel disease, or intestinal ulcers must not use cascara sagrada.

Cascara sagrada is not appropriate for treating constipation in children.

Adverse Effects:

Cascara sagrada can cause diarrhea and abdominal cramps. Moreover, it can injure the liver (Hawai’i Journal of Medicine & Public Health, June 2015).

Chronic use of laxatives may lead to excessive loss of potassium or other electrolytes, which may be dangerous. In addition, anthraquinones can cause pigmentation of the large bowel.

The most serious problem associated with chronic use, however, is that a person may become dependent on such a stimulant laxative and become unable to evacuate without it. This leads to problems that resemble ulcerative colitis.

Possible Interactions:

If cascara sagrada results in excessive potassium loss, heart rhythm irregularities may occur. This problem could be especially severe for people taking the heart drug Lanoxin.

It would be unwise to use cascara sagrada together with other herbal medicines that can cause potassium loss, such as aloe or licorice.

Medications such as hydrochlorothiazide, Lasix, Hygroton, Lozol, Bumex, and other potassium-wasting diuretics are probably incompatible with cascara sagrada, at least if it were used more than very occasionally.

Cascara sagrada, like other strong laxatives, may reduce the absorption of other medicines taken orally.

Rate this article
5- 1 rating

Today's Newsletter Reading List

    About the Author
    Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
    Tired of the ads on our website?

    Now you can browse our website completely ad-free for just $5 / month. Stay up to date on breaking health news and support our work without the distraction of advertisements.

    Browse our website ad-free
    • Nakasone ES & Tokeshi J, "A serendipitous find: A case of cholangiocarcinoma identified incidentally after acute liver injury due to Cascara sagrada ingestion." Hawai'i Journal of Medicine & Public Health, June 2015.
    • Chen Y et al, "Emodin and its combination with cytarabine induce apoptosis in resistant acute myeloid leukemia cells in vitro and in vivo." Cell Physiology and Biochemistry, Aug. 10, 2018. DOI: 10.1159/000492544
    • Chen Y et al, "Integration of bioinformatics and experiments to identify TP53 as a potential target in Emodin inhibiting diffuse large B cell lymphoma." Biomedicine & Pharmacotherapy, Nov. 2018. DOI: 10.1016/j.biopha.2018.07.168
    • Li N et al, "Emodin inhibits pancreatic cancer EMT and invasion by up‑regulating microRNA‑1271." Molecular Medicine Reports, Sep. 2018. DOI: 10.3892/mmr.2018.9304
    Join over 150,000 Subscribers at The People's Pharmacy

    We're empowering you to make wise decisions about your own health, by providing you with essential health information about both medical and alternative treatment options.

    Showing 2 comments
    Add your comment

    I have used aged Cascara Sagrada Bark with great success many times. It works every time and is quite gentle.
    I take it with a large amount of water before I go to sleep; the water does not cause an urge to urinate during the night (because it passes into the fecal matter?) and I wake up a few minutes early because I’ll have to defecate immediately, up to three times within an hour depending on the degree of constipation being relieved.

    As a eight year old child, I was often given what was then an over-the-counter laxative called CascaraQuinine Cold Tablets. I loved to take it, as I secretly enjoyed the pounding pulse, and hallucinations that occurred. When I told my mom that I was able to have the repeated nightmarish scenario at will, she was horrified and that was the end of my great drug times. Who knows what it may have been doing to my major organs.
    Even though now it appears to have only one ingredient, I personally would not like to know children have been given it.
    Considering the gory nightmares I began to have when I recently started taking Singulair (until I switched to administering it in the day, not later than 4 pm), I wonder if certain individuals are sensitive to many drugs. Perhaps some casual questioning about sleep and dreams should be part of a parent’s observation when a child receives any new drug.

    * Be nice, and don't over share. View comment policy^